[PATCH] arm64: dts: amlogic: odroid-go-ultra: use the RK818 RTC as rtc0

[Shigeaki Asai]

The ODROID-GO Ultra has two PMICs with an RTC each, RK818 and RK817,
and the SoC has the meson virtual RTC. Only vrtc has an alias, rtc0.

An RTC without an alias takes the lowest free number, and the RK817
RTC registers early, so it usually becomes rtc0, the RTC the system
time is set from at boot. The RK817 RTC seems to run without a 32kHz
crystal on this board: it ran about 1.5% fast while the board was on
and 14-17% slow while it was off. The RK818 RTC keeps time well:
with it as rtc0, the clock was off by less than a second after the
board was off, with no charger connected, for 12 hours 40 minutes.

Use the RK818 RTC as rtc0, and give the other two RTCs an alias as
well, so that the numbering does not depend on probe order.

Fixes: 62e73f000696 ("arm64: dts: amlogic: add initial Odroid Go Ultra DTS")
Assisted-by: claude-opus-5-5
Signed-off-by: Shigeaki Asai <y-asai.0816 at docomonet.jp>
---
 arch/arm64/boot/dts/amlogic/meson-g12b-odroid-go-ultra.dts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-go-ultra.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-go-ultra.dts
index 348baa4e6d84..86902f68d7d4 100644
--- a/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-go-ultra.dts
+++ b/arch/arm64/boot/dts/amlogic/meson-g12b-odroid-go-ultra.dts
@@ -18,7 +18,9 @@ / {
 
 	aliases {
 		serial0 = &uart_AO;
-		rtc0 = &vrtc;
+		rtc0 = &rk818;
+		rtc1 = &vrtc;
+		rtc2 = &rk817;
 	};
 
 	adc-joystick-left {
-- 
2.43.0